Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Cats & Casses

Pages: 1 | 2 | (show all)
SimonL
member


Reged: 09/17/07

C6 or 6" Intes MCT or C6-R?
      #6165030 - 10/29/13 05:38 PM

So would you recommend a SCT/MCT/refractor?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165080 - 10/29/13 06:15 PM

Any of those could be a good choice.

But to make the *right* choice, it depends a lot on what types of objects you want to observe, and where you plan to use the scope most of the time...


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: Jan Owen]
      #6165090 - 10/29/13 06:24 PM

The messier objects and planets in my backyard (urban) most of the time. I see you have refractors , SCT and Newtonian.
Which is your preferred scope?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165094 - 10/29/13 06:26 PM

Well, of course if you can afford $5000 for a 6" APO and another $2000 for a good used mount, then the 6" APO is going to be by far and away the best performing scope.

It will have better contrast on planets, better deep sky performance, and a far wider true field than these other designs.

A 6" acromat though is not the same thing as a 6" APO.

And don't let people convince you that you can turn a 6" acromat into a 6" APO with a filter. The damage from CA is not just the color fringing, but rather the energy removed from the Airy Disk, which lowers the performance to no better than a 4.5" to 5" ED refractor. The only thing left is the wide field performance.

If you are comparing 6" f/10 MCT to 6" SCT, then because the new Celestron scopes seem to have excellent quality, the difference will not be all that much.

If you like to do planets, an older 6" f/15 Intes will beat anything either of the f/10 scopes.

There is an option between all of these though.

If you can find a used MN66, you get the excellent contrast and wide field performance of a 6" APO, but you still have to ante up for a medium size mount.

So, you are comparing apples to go carts here by including 6" refractors because to get one with good performace, it needs to be an APO and this means that with the mount, you will spend 10 times as much as you would for a 6" SCT.

The big, fast achromats are simply not very good telescopes for much other than wide field, but if that is what you want, and if you can afford the mount, then go for it.

But a used MN66 is such a better scope than all of these other choices, that if you are seriously considering a 6" refractor, do yourself a favor and get the 6" Mak Newt.


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: Eddgie]
      #6165103 - 10/29/13 06:32 PM

Well these are all sort of the same in cost. I could add an 8" f/5 Newtonian to the mix. This should be good for wide fields plus all the above but much bulkier than a SCT or MCT.

Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165105 - 10/29/13 06:33 PM

And there are used C8's.

Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165121 - 10/29/13 06:40 PM

There are good Skywatcher 6" achromats that perform close to older 6" f/8 AP apo.

Post Extras: Print Post   Remind Me!   Notify Moderator  
BillP
Postmaster
*****

Reged: 11/26/06

Loc: Vienna, VA
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165164 - 10/29/13 07:04 PM

Quote:

Well these are all sort of the same in cost. I could add an 8" f/5 Newtonian to the mix. This should be good for wide fields plus all the above but much bulkier than a SCT or MCT.




All the scopes you mention have their pros and cons. So it all just depends on your preferences in the mix.

A C6-R is a big scope. The mount needs to be tall with legs extended if you are viewing anything near the zenith...otherwise you will be on the ground trying to access the eyepiece. It will do great with most everything, but will show color on planetary or lunar viewing which some folks do not like. You will get a 2.2 degree TFOV as max with a 2" eyepiece.

The SCTs and MCTs are closed tube and will have thermal equillibrium difficulties if your outdoor temps vary much. But they are small and convenient. Most have long focal ratios though so at ther native f/10 or f/15 the most TFOV you will get is 1.75 to 1.2 degrees with a 2" eyepiece...and their central baffles may not allow even that. Higher planetary magnifications though they can be great when in thermal equillibrium, better than the achromat for sure.

The 8" f/5 Newt is the biggest and heaviest probably of the group. It will need a Paracorr if you plan wide field. The nice thing though is that with something like a 40mm XW or 31T5 you can get a good, bright, and large patch of sky, around 2.3 to 2.5 degrees. Exit pupil with the 40mm and Paracorr is a bit over 7mm so better choice would be the 31T5 probably. The f/5 will also have a smaller central obstruction by far compared to that on say the SCT.

So just all depends on what you are after. The extra light pull of the 8" though over the 6" is significant, around 1.8x more light gathering. Extra resoltion as well. I've had all the other types of instruments, and now am experimenting with an 8" f/5 on a GEM mount (having a rotating tube is a must if on a GEM). Right now I am much preferring the 8" f/5 over the others because it has a good wide TFOV capability and gathers enough more light to make stuff like fainter Globs much more interesting than what a 6" SCT or MCT will show. If bulk is no issue then IMO the 8" Newt is best all around, if you want to maximize protability than the Celestron C6 is superb and gives a bright image as well. Would probably also get a .6x focal reducer with it though to flatten some of its field curvature out and give it better wide field performance.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eddgie
Postmaster
*****

Reged: 02/01/06

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165231 - 10/29/13 07:45 PM

I have owned both, and I can tell you without any reservation that a 6" f/8 achromat can in no way compare to a 6" APO.

Have owned three 6" f/8s, and an MN66 is a far better telescope.

But get what you like. It sounds like you may already have a refractor in mind. They are inexpensive and if you have a way to mount it, then go for it.

And if you decide you want to sell it, there will be someone else that will take it off of your hands.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165280 - 10/29/13 08:12 PM

I'm not certain I have a single most favorite scope... The scopes I have now have been acquired for a variety of different uses. Basically, most of them were bought to address specific interests of mine... So, within their own realm, they're each favorites...

Frankly, I probably use the 8" Newtonian the most. It has exceptional optics, and *enough* aperture to do double duty for either lunar/planetary, OR DSO's...

But when I want to get more serious about DSO's in general, I'll always choose the 12" (and it does put up superb lunar/planetary images as well). On the other hand, if I were to choose just the Double Cluster (a personal favorite object which I can easily spend an entire night on alone), I'm about as likely to grab any of them... Each one delivers the goods in their own special way...

But then, there's the 10" SCT, which also has excellent optics (replacement optics for the original set), can deliver stunning images (I do pay meticulous attention to collimation & getting & keeping the optics fully equilibrated with the surrounding air), so, given it's compact size for the aperture, and great images, it could steal your heart when the conditions are right...

I guess I sounded like a politician, there... Never gave you a clear-cut single answer... That's because I'm always wavering back & forth between my scopes as to which is my favorite...

BUT, if I can only recommend one of them, I suppose it'd be the 8" Newtonian, assuming you take the time to assemble one with equal optics & mechanicals...

While I was gone, I see you've also received some superb assistance from others here. This is a GREAT place to come for answers to questions like yours... Some very really well-experienced and helpful folks give of their time selflessly to help flesh out a variety of possible solutions. Hard to find a better place for that than here.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6165548 - 10/29/13 11:55 PM Attachment (34 downloads)

Now, for a more direct answer.

Directly to your interests, the messier objects and planets from an urban back yard, from the specific telescopes you have asked about, I'd probably recommend the Intes (or Intes Micro) MCT, if it's an f/10 (the f/15 would be slightly better for planets, and the f/10, with it's wider field, a bit better for the Messier Objects. The C6R would be no slouch on the Messier objects, either. But the other two would probably edge it slightly on the moon & planets, though it would be close.

For a a modest sum more, though, you could buy an 8" SCT, or a REALLY nice 8" f/6 Newtonian (which will take you deeper on the DSO's, show more planetary detail)... Those pesky Newtonians, if assembled from the right parts, deliver amazing views that, with the aid of a Paracorr, can deliver images you'd SWEAR were from an APO.

Edited by Jan Owen (10/30/13 12:21 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: Jan Owen]
      #6166349 - 10/30/13 12:56 PM

For the money I could get a C8 or C6R.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Joe Aguiar
Carpal Tunnel
*****

Reged: 02/10/07

Loc: none of your buss
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6166420 - 10/30/13 01:30 PM

wow tough call
the refractor is long and will need a decend mount so it will weight abit, but its good overall it has some colour but decent optics and vies

the mak will take longer to cool down and long FL means crisper views but fov is small, cooldown time may be 1 hr to 1.5 hrs

sct will be maybe the middle of both the other scopes so my option will be this one for u


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6166425 - 10/30/13 01:33 PM

If cost is a major issue, the C6R will deliver a lot for the money... Depends on how much chromatic aberration bothers you, when you're viewing bright objects... For most DSO's there won't BE any chromatic aberration, and the views will be quite nice... They are a bit long and more cumbersome, but there are a lot of happy C6R owners out there.

The SCT is more compact, and can deliver great images. They can be a little slow to equilibrate, compared to the Newt or refractor, but active cooling can be a big help, if the scope has this, or if it can easily be added. And the compact size can be a real blessing during setup and takedown.

The Newt will deliver slightly more aesthetically pleasing images, and a wider field for DSO's, at the expense of a longer tube. And, the Newt, if it's similar to mine, will also be a little more expensive (much of which comes from the Paracorr & Nagler eyepieces, and not the cost of the scope, but without which a level of the superior aesthetics would be lost).

The MCT will have superb views, similar to the Newt, with sharp images across the field, at low or high magnification, and no visually meaningful aberrations. It is compact like an SCT, but more expensive, and cooldown will be as long as an SCT or longer. If you're patient, and don't live where the temperature changes dramatically in a short time, they can be stunning.


Post Extras: Print Post   Remind Me!   Notify Moderator  
dweller25
Pooh-Bah


Reged: 08/30/07

Loc: Lancashire, UK
Re: C6 or 6" Intes MCT or C6-R? new [Re: Jan Owen]
      #6166438 - 10/30/13 01:37 PM

Whilst it's not on the OP's list but keeping to a 6" aperture - I would get a 6" F/8 Dobsonian with excellent optics.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Stelios
Carpal Tunnel
*****

Reged: 10/04/03

Loc: West Hills, CA
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6166695 - 10/30/13 03:45 PM

Quote:

For the money I could get a C8 or C6R.




A C8 (8" SCT) is, IMO, a *FAR* superior telescope to a C6R.

First of all the obvious: It has higher light grasp and resolution. Contrast is comparable. It has no false color unlike the *ginormous* false color of the C6R.

But there are the less obvious as well:

1) The C8 you can observe in comfort seated. The C6R will put you in all kinds of contortionistic positions.
2) The C6R requires a bigger mount than the C8. A CG-5 will hold a C8 like a baby, but trembles under the C6R.

The one advantage the C6R has is larger field of view.

Frankly, the main C6R appeal is that it's cheap. If you can afford something else, go that way.


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: Stelios]
      #6168728 - 10/31/13 03:26 PM

Well I like a C8 but I have to use it in the winter. There could be tube currents and long cool down times.
Also with UHC or OIII filter will C6-R be same as an 6" APO?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Eric63
scholastic sledgehammer


Reged: 06/16/12

Loc: Ottawa, Ontario
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6168751 - 10/31/13 03:36 PM

Winter is an issue where I live, but I simply plan ahead. I put my Mak (still in its case) outside (or in the trunk of my car) an hour before observing. If I change my mind later, I just bring it back in.

Eric


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6168849 - 10/31/13 04:28 PM

You can't get an achromat to APO performance via filters (but I haven't seen any test results from using narrow passband filters in side by side comparisons between an APO and an achromat).

You can get fairly close with a Chromacor, but they aren't in regular production any longer, to the best of my knowledge, and aren't inexpensive (except in comparison to the price difference between an achro and APO telescope)...

Edited by Jan Owen (10/31/13 04:37 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: C6 or 6" Intes MCT or C6-R? new [Re: Jan Owen]
      #6169252 - 10/31/13 09:14 PM

I've found an hour with my C6 in the dead of winter is enough equilibrium time. I personally wouldn't even remotely consider that 6" achro unless you are happy at low power. A C8 can cool down very fast so I'm told - 30 minutes) with a Lymax device that essentially blows outside air into the OTA .

I haven't done it specifically with that 6" achro but if you are entertaining ideas of great 300x shots of Plato or Mars you might want to lose the achro idea all together - certainly at that focal ratio/aperture. There are too many other far better choices.

Pete


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jan Owen
Pooh-Bah
*****

Reged: 02/12/06

Loc: Sun City West, Arizona
Re: C6 or 6" Intes MCT or C6-R? new [Re: azure1961p]
      #6169322 - 10/31/13 09:59 PM

You bring up a good point about the Lymax SCT cooler... I have one for my 10", and it has transformed that scope from one which often NEVER equilibrated all night long, to one that's ready to rock in less than an hour. And if you have to stop and catch the scope up on an evening when the temperatures are falling quickly, it doesn't take long after the initial big cooldown (but you may find yourself repeating the exercise several times through a long night)... Couldn't live without my Lymax and the Celestron f/6.3 reducer/corrector...

Post Extras: Print Post   Remind Me!   Notify Moderator  
spencerj
Pooh-Bah
*****

Reged: 11/17/04

Loc: Londonderry, NH
Re: C6 or 6" Intes MCT or C6-R? new [Re: Jan Owen]
      #6169968 - 11/01/13 10:41 AM

I have always been partial to the Intes and Intes Micro scopes, because . . . well . . . they are just cool. I have always liked the industrial tank-like build and excellent optics. Over the last 10 years, I have always owned at least one. I don't see that streak ending anytime soon.

Sure cool down is something you have to be aware of, but that is the case with all scopes. Eddgie is right about the MN66. In the 6" class, you will not find a more versatile and optically excellent scope for the money (especially if you find a good one with an upgraded focuser on the used market).


Post Extras: Print Post   Remind Me!   Notify Moderator  
RichD
Carpal Tunnel


Reged: 11/08/07

Loc: Derbyshire, UK
Re: C6 or 6" Intes MCT or C6-R? new [Re: spencerj]
      #6170083 - 11/01/13 11:44 AM

The MN66's are wonderful scopes. I think for the price and all round ability they are very hard to beat.

Used, they represent a great bargain.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Thomas A Davis
Pooh-Bah


Reged: 03/25/05

Re: C6 or 6" Intes MCT or C6-R? new [Re: RichD]
      #6170500 - 11/01/13 03:19 PM

Ditto that. I owned one, and it was as close to a 6" APO as
I've seen in a non-refractor design. Also, they are lighter
than the Intes MN61, so less of a mount is needed for it.

Tom


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: Thomas A Davis]
      #6174199 - 11/03/13 06:09 PM

I think the helical focuser and lack of range and small CO is a problem for the Intes MN scopes for wide fields and imaging.

Post Extras: Print Post   Remind Me!   Notify Moderator  
orion61

*****

Reged: 10/20/07

Loc: Birthplace James T Kirk
Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6174250 - 11/03/13 06:38 PM

in defense of the C6-R use an Orion anti-fringe filter with a light Blue color filter, it gets rid of the false color and sharpens the image without that ghastly pale yellow tint.
As far as Intes scopes I have only had fair luck with their MCT's my first MK 65 had horrible SA 5 rings, the second mk65 was vg, not as good as my Meade 7" tho, my last MK66 was a reg 1/6th and got out performed big time by my C8.
Haven't had the chance to view through one of the "Deluxe" 1/8th wave scopes. Some swear by them so they must be pretty good.


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: orion61]
      #6175425 - 11/04/13 01:09 PM

I think the C6-R is my preference.
It should rival reflective telescopes much larger in size because of less scatter, more contrast.


Post Extras: Print Post   Remind Me!   Notify Moderator  
SimonL
member


Reged: 09/17/07

Re: C6 or 6" Intes MCT or C6-R? new [Re: orion61]
      #6175426 - 11/04/13 01:10 PM

Yes I am deciding on an antifringing filter. Someone suggested a simple yellow filter.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Thomas A Davis
Pooh-Bah


Reged: 03/25/05

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6175508 - 11/04/13 01:48 PM

Quote:


I think the helical focuser and lack of range and small CO is a problem for the Intes MN scopes for wide fields and imaging.






When I was imaging with mine, I had a smaller chip CCD. No
issue then. Now with larger chips and DSLRs, yes the small
CO presents an issue. What you have to understand is that
a good 6" APO is going to cost considerably more. I had
two in that range (TEC160 Fluorite, and TMB152). Both were
fantastic for imaging, and were uncompromising for visual.

Where the MN66 shines is as a lower cost visual alternative
to a high-end APO. Wide field not really that much of a
problem, since you can get a decent wide field at F/6 with
a 1 1/4" eyepiece compared to an SCT and a 2". The smaller
CO secondary is needed to get maximum contrast. It is a
compromise design, but with excellent results in the areas
of intended use. Not a one-size fit-all solution.

The supplied focuser worked, but a Moonlite replacement
definitely works better. Intes-Micro also made a Mak-Newt
called the MN65 that was 6.5" with a larger secondary.
That would be better for imaging.

Tom


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jeff B
Carpal Tunnel
*****

Reged: 12/30/06

Re: C6 or 6" Intes MCT or C6-R? new [Re: SimonL]
      #6177203 - 11/05/13 11:33 AM

Quote:

So would you recommend a SCT/MCT/refractor?




The Mak-Newt.

Next question?


Post Extras: Print Post   Remind Me!   Notify Moderator  
saemark30
Pooh-Bah


Reged: 02/21/12

Re: C6 or 6" Intes MCT or C6-R? new [Re: Jeff B]
      #6177273 - 11/05/13 12:16 PM

A good 8" f/5 Newtonian plus Paracorr is about as good as a MN but cheaper and more aperture.

Post Extras: Print Post   Remind Me!   Notify Moderator  
saemark30
Pooh-Bah


Reged: 02/21/12

Re: C6 or 6" Intes MCT or C6-R? new [Re: saemark30]
      #6179857 - 11/06/13 07:15 PM

The Russian Mak coatings seem a bit warmer and duller than similar size Newtonian mirrors, anyone else want to chime in?

Post Extras: Print Post   Remind Me!   Notify Moderator  
spencerj
Pooh-Bah
*****

Reged: 11/17/04

Loc: Londonderry, NH
Re: C6 or 6" Intes MCT or C6-R? new [Re: saemark30]
      #6180790 - 11/07/13 11:09 AM

Quote:

The Russian Mak coatings seem a bit warmer and duller than similar size Newtonian mirrors, anyone else want to chime in?




The older Intes MN61 scopes had a warmer tone and the mirror and meniscus coatings were not up to today's standards. The warmer tone was just from he glass used. My old MK-66 had the same warm tone. Some Televue Naglers had a warm tone. That is not necessarily a bad thing. I actually found on some targets like Jupiter and Mars that it was beneficial. On most targets, it was not even noticed.

Early reviews of those scopes commonly stated that the optics were outstanding, but the image was a little dimmer than expected for the aperture. Can't say I recall too many reviews of Intes or IM Mak Newt scopes where the images through the scope were described as "dull".

The IM scopes of the last 10 years have improved coatings and a neutral tone. They are as bright as you would expect for their aperture.


Post Extras: Print Post   Remind Me!   Notify Moderator  
spencerj
Pooh-Bah
*****

Reged: 11/17/04

Loc: Londonderry, NH
Re: C6 or 6" Intes MCT or C6-R? new [Re: saemark30]
      #6180803 - 11/07/13 11:20 AM

Quote:

A good 8" f/5 Newtonian plus Paracorr is about as good as a MN but cheaper and more aperture.




I definitely do not have first-hand experience with this comparison, but Mak Newts have a tremendous reputation as planetary scopes. I don't recall a lot of (make that any) instances where 8" F5 Newtonians with a Paracorr were given the same high praise. As for the cost savings . . . guess that depends on what you pay for the Paracorr.

P.S. If I were looking for a planetary Newtonian, I think I would lean towards something with an 8" Zambuto mirror at F6 or slower.


Post Extras: Print Post   Remind Me!   Notify Moderator  
saemark30
Pooh-Bah


Reged: 02/21/12

Re: C6 or 6" Intes MCT or C6-R? new [Re: spencerj]
      #6181604 - 11/07/13 06:20 PM

I know a number of Russian MCT owners who all thought the images were dim, and less sharp than a fine Newtonian of same size!
So a MK67 was bested by a RV6 and a 8" MCT had poor thermals that last for hrs and hrs.
ATM's make their own Newtonian mirrors and aim for perfection and considerable savings in money but not time.
There is no meed for a Paracorr at f/6 and some people think the Ethos can deal with f/4.5 cones just fine.
I just do have experience with large MN's mostly because they are rare and expensive.


Post Extras: Print Post   Remind Me!   Notify Moderator  
spencerj
Pooh-Bah
*****

Reged: 11/17/04

Loc: Londonderry, NH
Re: C6 or 6" Intes MCT or C6-R? new [Re: saemark30]
      #6182451 - 11/08/13 08:38 AM

Everyone's experience is different and equally valid. But reading back through old reviews of Russisn MCTs or MNs, dim and less sharp are not terms you will see often. The Intes and IM optics are generally considered very, very good--especially the deluxe models.

If the image is not perfectly sharp, there is an issue somewhere. Whether it is collimation or the scope is not cooled down or the seeing is poor. All of those conditions would effect a Newtonian as well.


Post Extras: Print Post   Remind Me!   Notify Moderator  
brianb11213
Postmaster
*****

Reged: 02/25/09

Loc: 55.215N 6.554W
Re: C6 or 6" Intes MCT or C6-R? new [Re: spencerj]
      #6182883 - 11/08/13 12:36 PM

Quote:

Everyone's experience is different and equally valid. But reading back through old reviews of Russisn MCTs or MNs, dim and less sharp are not terms you will see often. The Intes and IM optics are generally considered very, very good--especially the deluxe models.



Yeah. The older Russian scopes are using coated optics but not multicoated like modern Chinese types. Also the mirror coatings would be aluminimum (80%) rather than dielectric (99%). This will have a barely perceptible effect on "dimming" of the images, reducing the limiting magnitude by around 0.4 magnitude.

This "mild filtration" is actually beneficial for bright objects like the moon & major planets.

Quote:

If the image is not perfectly sharp, there is an issue somewhere. Whether it is collimation or the scope is not cooled down or the seeing is poor. All of those conditions would effect a Newtonian as well.



Indeed. But the sealed tube of a Mak seems to be a lot harder to keep close enough to ambient than the open tube of a Newtonian. IMHO active (fan) ventilation is required in all but the smallest Maks (those under 4" aperture). The Intes & IM tubes don't seem to be as bad at cooling as the Skywatcher / Orion & Meade Maks but they can still struggle if you have rapid temperature changes.

FWIW the C6 tube is horrible for tube currents. It simply won't track rapid temp changes, the Lymax cat cooler is too long to fit & the thin-walled dark coloured metal tube generates its own tube currents as the sky-facing surface cools by radiation faster than the ground-facing surface.


Post Extras: Print Post   Remind Me!   Notify Moderator  
vahe
scholastic sledgehammer


Reged: 08/27/05

Loc: Houston, Texas
Re: C6 or 6" Intes MCT or C6-R? new [Re: brianb11213]
      #6182958 - 11/08/13 01:20 PM

Quote:


Also the mirror coatings would be aluminimum (80%) rather than dielectric (99%). This will have a barely perceptible effect on "dimming" of the images, reducing the limiting magnitude by around 0.4 magnitude.






Dielectric coating are not typically suitable for mirrors, the problem with dialectric is the multiple coatings applied on top of one other, as the result the final surface is generally not as smooth as the mirror substrate.
Dialectrics are offered for diagonals, the surface smoothness is not an issue since in high poser observations only the very center of diagonal mirror is employed.
Enhanced coatings are what one sees in mirrors, they generally have high reflectivity that settles down to 94% - 96% after initial period of aging.

Vahe


Post Extras: Print Post   Remind Me!   Notify Moderator  
saemark30
Pooh-Bah


Reged: 02/21/12

Re: C6 or 6" Intes MCT or C6-R? new [Re: vahe]
      #6185098 - 11/09/13 05:12 PM

Also if you like observing double stars the refractor will be better with unequal brightness doubles. The colors will be more saturated with the all lens system IMHO.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
9 registered and 16 anonymous users are browsing this forum.

Moderator:  Starman27, kkokkolis 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1802

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics